Analysis of slabs spanning in two directions under concentrated load

الملخص EN

The analysisofrectangulartwo-wayslabssubjectedtoconcentratedloaduniformlydis- tributed overdefinedareaafterdispersiondowninthetwodirectionstothereinforcementisaprac- tically importantcase.AspresentedbyEgyptiancodefordesignandconstructionofconcrete structures ECCS203-2007,theanalysisofthisproblemcanbeperformedbyusingtheelasticanal- ysis orbyusinganapproximatemethodwhichdependsonthedistributionoftheconcentratedload in thetwodirectionsbytheratioofthelonglengthandshortlengthoftherectangularslab.

Significant differencesbetweentheresultsofthesemethodsmusttakeourattention.Analternative approximate methodfordeterminingthebendingmomentsoftheslabunderstudyinthetwodirec- tions isinvestigatedinthispaperbasedontheelasticanalysis.Twoclosed-formexpressionswere obtained whichdescribetherelationbetweenthebendingmomentsandallfactorsthataffectit (the spanratio,thedimensionsratiooftheloadedareaandtheratiobetweentheshortspanto the parallellengthoftheloadedarea).Comparisonsbetweenthestrainingactionsinthetwodirec- tions resultingfromthepresentanalysisandthesefromtheexistingapproximatemethodofthe ECCS 203-2007withthoseobtainedbyinternationalcodesasBritishStandardsBS8110andthose obtained byfiniteelementmethodaregivenalsointhispaper